Method and apparatus for protecting tooling in a lead-free bath

ABSTRACT

The disclosed embodiments represent a method and apparatus for improving a lead-free electroplating process in the manufacture of semiconductor devices. To prevent the buildup of undesirable copper or bismuth on a conveyor belt and the associated tooling used to transport integrated circuit devices through an electroplating bath, a metal more noble than copper or bismuth, depending on which is used as a plating metal, is plated onto the surface of the conveyor belt and associated tooling.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This present invention relates generally to the field ofintegrated circuit manufacture and, more specifically, to the field ofplating metal on the external lead frames of integrated circuitpackages.

[0003] 2. Description of the Related Art

[0004] This section is intended to introduce the reader to variousaspects of art that may be related to various aspects of the presentinvention, which are described and/or claimed below. This discussion isbelieved to be helpful in providing the reader with backgroundinformation to facilitate a better understanding of the various aspectsof the present invention. Accordingly, it should be understood thatthese statements are to be read in this light, and not as admissions ofprior art.

[0005] Computer systems typically include a variety of electricallyinterconnected integrated circuit (I/C) packages which perform a varietyof functions, including memory and processing functions. As integratedcircuit devices have become more complex, so have the processes formanufacturing them. Integrated circuit manufacturers, such as theassignee of the present invention, invest heavily in state-of-the-artfabrication facilities (called “fabs”). Building complex integratedcircuits involves processes that have many steps and sub-steps. Many ofthese processes employ chemical reactions that depend on the propertiesof the various types of metals used for different purposes in theintegrated circuit manufacturing process. Different combinations ofmetals and chemicals are used in different processes because of theirunique characteristics.

[0006] Electroplating is a process that may be used for many differentpurposes during the manufacturing of integrated circuits. In the processof electroplating, a metal or alloy of metals is deposited on a desiredobject to be plated. The object to be plated, which is frequently adifferent type of metal, is placed in a bath containing an electrolyticsolution containing metal ions, leveling agents, and antioxidants. Theobject that is plated is sometimes referred to as a cathode. A quantityof the metal or metal alloy to be plated (or disposed) onto the objectis also placed in the bath. In electroplating, the metal or metal alloythat is to be plated onto another object may be referred to as an anode.When an electric current is passed through the bath, an electric circuitthat includes the plating metal (anode) and the object to be plated(cathode) is completed. The electric current causes metal ions that arepresent in the plating solution to be deposited on the object that isbeing plated. The metal ions from the electrolytic solution are replacedby the anode of the electric circuit, but the replacement of ions is notcompletely efficient.

[0007] One use of electroplating in the context of manufacturingintegrated circuits is for depositing metal on the external electricalconnections on the package of an integrated circuit. These externalconnections may take on any number of forms and are sometimes called“pins” or “leads.” The structure that holds the pins or leads togetheron the integrated circuit package is sometimes referred to as a “leadframe.” It is desirable to electroplate the lead frames of integratedcircuit packages to provide a solderable surface so that the leads maybe effectively soldered to a circuit board. Also, electroplating of thelead frame tends to prevent corrosion of the leads.

[0008] When integrated circuit devices are plated, each integratedcircuit device is typically passed through an electroplating bath. Thebath contains an electrolytic solution that may be optimized to transfera particular metal to the target lead frames on the integrated circuitpackages. To increase productivity, integrated circuit devices may besystematically and continuously passed through the electrolytic bath ona conveyor belt or the like. Each integrated circuit package may besecured to the conveyor belt with a metallic hook, clip, or othersimilar means. An electric current is passed through the electrolyticbath, and the pins of each integrated circuit package in turn are made acathode in the electric circuit. A metal that is intended to be platedon the lead frame is disposed in the electrolytic bath and that metalforms an anode in the electric circuit that includes the lead frame andpins. As the integrated circuit package moves through the bath, its leadframe is plated with the plating material.

[0009] Pure tin (Sn) may be used as a plating material because of itsexcellent solderability characteristics. Tin is also very effective atpreventing corrosion. However, the use of pure tin or nearly pure tin asa plating material results in a problem known as “whiskering.”Whiskering is an expression that refers to the development of tinyfilaments of tin on the lead frame after being plated with pure ornearly pure tin. Tin whiskers are thought to be the result ofrecrystallization to relieve stress formed during plating. Whiskering isundesirable because the tiny tin filaments can contact and short outagainst other pins of the integrated circuit package or other areas of acircuit board on which the integrated circuit device is to be mounted.At this time, the phenomenon of whiskering is not fully understood andno industry testing standards are in place to define whether a coatingis “whisker free.” To avoid tin whiskering, lead frames plated with puretin or nearly pure tin may be subjected to hot dipping or reflowingabove the melting point of tin. Alternatively, the addition of a minimumof 2% lead (Pb) to electroplated tin (Sn) has been determined to be veryeffective in reducing tin whiskering. Using a tin/lead (Sn/Pb) platingalloy to avoid whiskering may be more desirable than hot dipping orreflowing at elevated temperatures because improved process control ispossible with tin/lead (Sn/Pb) plating. Accordingly, plating lead frameswith a tin/lead (Sn/Pb) alloy instead of pure or nearly pure tin (Sn)has become a standard practice in the integrated circuit manufacturingindustry.

[0010] One problem with typical plating processes is that lead (Pb) isbecoming increasingly undesirable as a plating metal. Because of theundesirability of lead (Pb), its use in alloys with tin is alsoundesirable. Some alternatives to the use of Sn/Pb alloys have beendiscovered. Alloys of tin and copper (chemical symbol Cu), for example,are one such alternative. In symbol notation, these alloys are sometimesreferred to as Sn/Cu alloys. Alloys of tin and bismuth (chemical symbolBi) are also alternatives to the use of Sn/Pb alloys. Tin/bismuth alloysare sometimes referred to using the symbol Sn/Bi.

[0011] Unfortunately, the use of Sn/Cu and Sn/Bi alloys have someundesirable side effects. When Sn/Cu and Sn/Bi alloys are used as thecathode for electroplating, deposits of copper (in the case of Sn/Cualloys) or bismuth (in the case of Sn/Bi alloys) tend to form on thesurfaces of conveyor belts and clips or hooks used to secure integratedcircuit packages to the conveyor belts. This happens through a processknown as immersion plating, which occurs during periods of time when noelectric current is being applied to the electrolytic plating solutionin the associated electroplating bath. The resulting deposits of copperor bismuth significantly shorten the life of tooling such as conveyorbelts and the associated the hooks or clips. The shortening of the lifeof the tooling results because the immersion plates are stripped offduring the normal operation of the plating line. After stripping, thetooling is again subject to immersion plating when it is reused.Immersion plating is a galvanic replacement reaction that is selfpassivating. In other words, the belts and associated hooks and clipsare essentially consumed because they are continually being stripped andsubjected to subsequent immersion plating. A method and apparatus thatreduces the effects of immersion plating on conveyor belts andassociated tooling would be highly desirable.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing and other advantages of the invention will becomeapparent upon reading the following detailed description and uponreference to the drawings in which:

[0013]FIG. 1 is a perspective view of an electroplating machine;

[0014]FIG. 2 is a top view of an operational portion of anelectroplating machine according to an embodiment of the presentinvention;

[0015]FIG. 3 is a cross-sectional view of the operational portion of theelectroplating machine shown in FIG. 2 taken along line 2-2 of FIG. 2;

[0016]FIG. 4 is a detail view showing the connection of an integratedcircuit device to the electroplating machine shown in FIG. 1 and FIG. 2;

[0017]FIG. 5 is a cross sectional view showing a surface of a conveyorbelt or associated tooling that has been plated according to the presentinvention; and

[0018]FIG. 6 is a flow diagram illustrating an electroplating processaccording to the present invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0019] One or more specific embodiments of the present invention will bedescribed below. In an effort to provide a concise description of theseembodiments, not all features of an actual implementation are describedin the specification. It should be appreciated that in the developmentof any such actual implementation, as in any engineering or designproject, numerous implementation-specific decisions must be made toachieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure.

[0020] Turning now to the drawings, FIG. 1 is a perspective view of anelectroplating machine that may be used to electroplate the lead framesof integrated circuit devices. The electroplating machine is generallyreferred to by the reference numeral 1. As described below, the platingmachine 1 may be adapted to deposit a plating metal on the lead framesof integrated circuit packages. The integrated circuit packages may beconnected to a conveyor belt (see FIG. 2 and FIG. 3) and moved throughthe operational portions of the plating machine 1 for efficientprocessing.

[0021]FIG. 2 is a top view of an operational portion of anelectroplating machine according to an embodiment of the presentinvention. The operational portion of the electroplating machine isrepresented generally by the reference numeral 10. A reservoir 12contains an electrolytic solution 14. A sparger 13 having a U-shapedcross section (see FIG. 3) is disposed within the electrolytic bath 12.The sparger 13 is adapted to deliver the electrolytic solution 14 to thereservoir 12. One or more metal anodes 15 are disposed at variouslocations within the electrolytic bath 12. The metal from the metalanodes 15 is intended to be deposited on the lead frames ofsemiconductor packages during operation of the electroplating machine.The metal 15 may be comprised of pure or nearly pure tin (Sn) instead ofan alloy of tin and copper (Cu) or bismuth (Bi). If pure or nearly puretin is employed, copper (Cu) or bismuth (Bi) may be resupplied to theelectrolytic solution 14 by adding concentrated solutions of Cu or Biduring operation of the plating machine 1 (FIG. 1).

[0022] A conveyor belt 16 is disposed to transport integrated circuitpackages 18 through the electrolytic solution 14 contained in theelectrolytic bath 12. The integrated circuit packages 18 are secured tothe conveyor belt 16 by clips (see FIG. 3). A motor 24 is adapted todrive the conveyor belt 16 so that the integrated circuit packages 18are passed through the electrolytic solution 14 in the electrolytic bath12. The details of the construction of the motor 24 and the connectionof the motor 24 to the conveyor belt 16 are matters of design choice andare not believed to be crucial aspects of the invention.

[0023]FIG. 3 is a cross-sectional view of the operational portion of theelectroplating machine shown in FIG. 2 taken along line 2-2 of FIG. 2.Each integrated circuit device 18 is held to the conveyor belt 16 by aclip 20. Each of the metal anodes 15 is held in place by a hook 22 a, 22b. The conveyor belt 16 is connected to the negative side of a powersource and the metal anodes 15, via the hooks 22 a, 22 b, are connectedto the positive side of a power source. As set forth above, the conveyorbelt 16 and the clips 20 and hooks 22 a, 22 b have been susceptible tocollecting deposits of copper or bismuth (depending on the compositionof the metal anodes 15) through the process of immersion plating, whichtypically occurs when no electric current is passed through theelectrolytic solution 14. Immersion plating typically occurs when theplating machine is not in normal operation.

[0024] The details of how the integrated circuit device 18 is secured tothe conveyor belt 16 are shown in FIG. 4. The clip 20 secures theintegrated circuit 18 to the conveyor belt 16 and provides an electricalconnection between the integrated circuit 18 and the cathode. Theintegrated circuit 18 includes a lead frame 23 that is to be platedduring normal operation of the plating machine 1 (FIG. 1).

[0025] As explained below, the accumulation of deposits on the conveyorbelt 16 may be prevented by plating the conveyor belt 16 with a layer ofmetal that is more noble than the Cu or Bi. Similarly, the clips 20 andhooks 22 a, 22 b, as well as any other portion of the machine 1 that maybe susceptible to undesirable copper or bismuth plating, may beprotected by plating them with similar metal layers.

[0026] Deposits formed by immersion plating of the conveyor belt 16 andother tooling will be prevented or significantly reduced if the platedmetal layers on each of those components are more noble than thedeposited component of the metal anodes 15. For example, if thecomposition of the metal anodes 15 is tin (Sn) and the electrolyticsolution 14 contains ions of copper (Cu) (or if the metal anodes arecomprised of an alloy of tin and copper (Sn/Cu)), the depositedcomponent will be copper. This means that, absent a plated layer that ismore noble than copper, the conveyor belt 16 and other tooling is likelyto accumulate deposits of copper by immersion plating. As anotherexample, if the composition of the metal anodes 15 is tin (Sn) and theelectrolytic solution 14 contains ions of bismuth (Bi) (or if the metalanodes are comprised of an alloy of tin and bismuth (Sn/Bi)), thedeposited component will be bismuth. This means that, absent a platedlayer that is more noble than bismuth, the conveyor belt 16 and othertooling is likely to accumulate deposits of bismuth by immersionplating.

[0027] Noble metals are generally characterized by a lack of chemicalreactivity. In particular, noble metals do not react significantly toacids and are not susceptible to atmospheric corrosion. A metal is saidto be “more noble” than a second metal if the “more noble” metal has ahigher electrode potential than the second metal. Examples of metalsthat are more noble than copper or bismuth include, for example, silver,gold, palladium and platinum. The determination of whether a given metalis more noble than another metal can readily be performed by one ofordinary skill in the art.

[0028] In the disclosed embodiments, alloys of metals that are morenoble than copper or bismuth (not just pure or nearly pure metals) mayalso be employed as plating materials. For example, gold alloys may beused as a plating material to avoid deposits on the conveyor belt 16 andassociated hooks 22 a, 22 b or clips 20. Gold alloys are typicallyharder than pure gold and, thus, less susceptible to mechanical wear asthe electroplating machine 1 operates In one known gold alloy, cobalt(Co) is alloyed with gold (Au) to form an alloy sometimes referred to as“hard Au.”

[0029] If the lead frame 23 of the integrated circuit component 18 beingplated is not comprised of copper (Cu), then copper (Cu) may be platedonto the belts and associated tooling to reduce or prevent the effectsof immersion plating. Similarly, copper (Cu) plating may be used as theplating material on the conveyor belt 16 and associated tooling whenpure tin (Sn) or alloys of tin and copper (Sn/Cu) or alloys of tin andbismuth (Sn/Bi) are being plated onto the lead frames 23 of integratedcircuit 18 except when the lead frame 23 itself is copper (Cu).

[0030] Examples of plating solutions that may be used to plate theconveyor belts 16, hooks 22 a, 22 b and/or clips 20 of a plating machineare Engelhard-Clal Supermex 230 Immersion Au solution or 100 ppm Pd/Cldissolved in HCl. The former solution is used to plate gold (Au) ontothe conveyor belt 16 and associated tooling. The latter solution is usedto plate palladium (Pd) onto the conveyor belt 16 and associatedtooling.

[0031]FIG. 5 is a cross sectional view of the surface of a metalcomponent that has been plated according to the present invention. Themetal 28 shown in FIG. 5 corresponds to the unplated surface of theconveyor belt 16, the clips 20, the hooks 22 a, 22 b or any othersurface of the electroplating machine 1 (FIG. 1) that is platedaccording to the present invention. A noble metal layer 19 is depictedas being disposed on the surface 28. The noble metal layer 19 may bedeposited on the surface 28 by any known method, including, for example,electroplating.

[0032]FIG. 6 is a flow diagram illustrating an exemplary embodiment ofan electroplating process according to the present technique. Theoverall plating process is referred to generally by the referencenumeral 30. Integrated circuit packages are typically pre-cleaned priorto electroplating. (block 32). The integrated circuit packages are alsotypically rinsed prior to being pre-dipped in plating acid (blocks 34and 36). An additional rinsing operation may also be performed (block37). The integrated circuit packages may undergo a plating bath using aplating machine such as the plating machine described above withreference to FIG. 1 (block 38). After processing in the plating bath,integrated circuit packages are typically cleaned and dried (blocks 40and 42).

[0033] While the invention may be susceptible to various modificationsand alternative forms, specific embodiments have been shown by way ofexample in the drawings and will be described in detail herein. However,it should be understood that the invention is not intended to be limitedto the particular forms disclosed. Rather, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the invention as defined by the following appended claims.

What is claimed is:
 1. A plating machine clip for securing a device forprocessing in an electrolytic bath, comprising: a plating machine cliphaving a metal more noble than copper plated thereon.
 2. The platingmachine clip of claim 1 wherein the metal comprises gold.
 3. The platingmachine clip of claim 1 wherein the metal comprises silver.
 4. Theplating machine clip of claim 1 wherein the metal comprises palladium.5. The plating machine clip of claim 1 wherein the metal comprisesplatinum.
 6. A plating machine clip for securing a device for processingin an electrolytic bath, comprising: a plating machine clip having ametal more noble than bismuth plated thereon.
 7. The plating machineclip of claim 6 wherein the metal comprises gold.
 8. The plating machineclip of claim 6 wherein the metal comprises silver.
 9. The platingmachine clip of claim 6 wherein the metal comprises palladium.
 10. Theplating machine clip of claim 6 wherein the metal comprises platinum.11. A plating machine hook for securing a device in an electrolyticbath, comprising: a plating machine hook having a metal more noble thancopper plated thereon.
 12. The plating machine hook of claim 11 whereinthe metal comprises gold.
 13. The plating machine hook of claim 11wherein the metal comprises silver.
 14. The plating machine hook ofclaim 11 wherein the metal comprises palladium.
 15. The plating machinehook of claim 11 wherein the metal comprises platinum.
 16. A platingmachine hook for securing a device in an electrolytic bath, comprising:a plating machine hook having a metal more noble than bismuth platedthereon.
 17. The plating machine hook of claim 16 wherein the metalcomprises gold.
 18. The plating machine hook of claim 16 wherein themetal comprises silver.
 19. The plating machine hook of claim 16 whereinthe metal comprises palladium.
 20. The plating machine hook of claim 16wherein the metal comprises platinum.
 21. A plating machine conveyorbelt for conveying a device through an electrolytic bath, comprising: aplating machine conveyor belt having a metal more noble than copperplated thereon.
 22. The plating machine conveyor belt of claim 21wherein the metal comprises gold.
 23. The plating machine conveyor beltof claim 21 wherein the metal comprises silver.
 24. The plating machineconveyor belt of claim 21 wherein the metal comprises palladium.
 25. Theplating machine conveyor belt of claim 21 wherein the metal comprisesplatinum.
 26. A plating machine conveyor belt for conveying a devicethrough an electrolytic bath, comprising: a plating machine conveyorhaving a metal more noble than bismuth plated thereon.
 27. The platingmachine conveyor belt of claim 26 wherein the metal comprises gold. 28.The plating machine conveyor belt of claim 26 wherein the metalcomprises silver.
 29. The plating machine conveyor belt of claim 26wherein the metal comprises palladium.
 30. The plating machine conveyorbelt of claim 26 wherein the metal comprises platinum.
 31. A platingmachine for disposing a first metal comprising copper on a device,comprising: an electrolytic bath containing an electrolytic solutioncomprising the first metal; a conveyor belt adapted to transport thedevice through the electrolytic bath, the conveyor belt having a secondmetal more noble than copper plated thereon to prevent the first metalfrom depositing on the conveyor belt via immersion plating; and a motoradapted to drive the conveyor belt.
 32. The plating machine of claim 31wherein the device is an integrated circuit device.
 33. The platingmachine of claim 31 wherein the second metal comprises gold.
 34. Theplating machine of claim 31 wherein the second metal comprises silver.35. The plating machine of claim 31 wherein the second metal comprisespalladium.
 36. The plating machine of claim 31 wherein the second metalcomprises platinum.
 37. The plating machine of claim 31, comprising aclip adapted to secure the device to the conveyor belt, the clip havinga third metal more noble than copper plated thereon.
 38. The platingmachine of claim 37, wherein the third metal comprises gold.
 39. Theplating machine of claim 37, wherein the third metal comprises silver.40. The plating machine of claim 37, wherein the third metal comprisespalladium.
 41. The plating machine of claim 37, wherein the third metalcomprises platinum.
 42. A plating machine for disposing a first metalcomprising bismuth on a device, comprising: an electrolytic bathcontaining an electrolytic solution comprising the first metal; aconveyor belt adapted to transport the device through the electrolyticbath, the conveyor belt having a second metal more noble than bismuthplated thereon to prevent the first metal from depositing on theconveyor belt via immersion plating; and a motor adapted to drive theconveyor belt.
 43. The plating machine of claim 42 wherein the device isan integrated circuit device.
 44. The plating machine of claim 42wherein the second metal comprises gold.
 45. The plating machine ofclaim 42 wherein the second metal comprises silver.
 46. The platingmachine of claim 42 wherein the second metal comprises palladium. 47.The plating machine of claim 42 wherein the second metal comprisesplatinum.
 48. The plating machine of claim 42, comprising a clip adaptedto secure the device to the conveyor belt, the clip having a third metalmore noble than bismuth plated thereon.
 49. The plating machine of claim48, wherein the third metal comprises gold.
 50. The plating machine ofclaim 48, wherein the third metal comprises silver.
 51. The platingmachine of claim 48, wherein the third metal comprises palladium. 52.The plating machine of claim 48, wherein the third metal comprisesplatinum.
 53. A method of electroplating at least a portion of anintegrated circuit package, the method comprising the acts of: securingthe integrated circuit device to a device that is plated with a metalmore noble than copper; and electroplating the at least a portion of theintegrated circuit device in a plating bath;
 54. The method of claim 53,further comprising the act of pre-cleaning the at least a portion of theintegrated circuit device.
 55. The method of claim 53, furthercomprising the act of rinsing the at least a portion of the integratedcircuit device.
 56. The method of claim 53, further comprising the actof pre-dipping the at least a portion of the integrated circuit devicein plating acid.
 57. The method of claim 53, further comprising the actof cleaning the at least a portion of the integrated circuit device. 58.The method of claim 53, further comprising the act of drying the atleast a portion of the integrated circuit device.
 59. The method ofclaim 53, further comprising the act of disposing a metal comprising anSn/Cu alloy in the plating bath.
 60. The method of claim 53, furthercomprising the act of transporting the integrated circuit device throughthe plating bath.
 61. A method of electroplating at least a portion ofan integrated circuit device, the method comprising the acts of:securing the integrated circuit device to a device that is plated with ametal more noble than bismuth; and electroplating the at least a portionof the integrated circuit device in a plating bath.
 62. The method ofclaim 61, further comprising the act of pre-cleaning the at least aportion of the integrated circuit device.
 63. The method of claim 61,further comprising the act of rinsing the at least a portion of theintegrated circuit device.
 64. The method of claim 61, furthercomprising the act of pre-dipping the at least a portion of theintegrated circuit device in plating acid.
 65. The method of claim 61,further comprising the act of cleaning the at least a portion of theintegrated circuit device.
 66. The method of claim 61, furthercomprising the act of drying the at least a portion of the integratedcircuit device.
 67. The method of claim 61, further comprising the actof disposing a metal comprising an Sn/Bi alloy in the plating bath. 68.The method of claim 61, further comprising the act of transporting theintegrated circuit device through the plating bath.
 69. A platingmachine, comprising: a reservoir adapted to contain an electrolyticsolution comprising copper; a conveyor adapted to transport a devicethrough the reservoir, the conveyor having a metal more noble thancopper disposed there on; and a motor adapted to drive the conveyor. 70.The plating machine of claim 69 wherein the metal comprises gold. 71.The plating machine of claim 69 wherein the metal comprises silver. 72.The plating machine claim 69 wherein the metal comprises palladium. 73.The plating machine of claim 69 wherein the metal comprises platinum.74. The plating machine of claim 69, comprising a clip adapted to securethe device to the conveyor, the clip having a second metal more noblethan copper plated thereon.
 75. The plating machine of claim 74, whereinthe second metal comprises gold.
 76. The plating machine of claim 74,wherein the second metal comprises silver.
 77. The plating machine ofclaim 74, wherein the second metal comprises palladium.
 78. The platingmachine of claim 74, wherein the second metal comprises platinum.
 79. Aplating machine, comprising: a reservoir adapted to contain anelectrolytic solution comprising bismuth; a conveyor adapted totransport a device through the reservoir, the conveyor having a metalmore noble than bismuth disposed there on; and a motor adapted to drivethe conveyor.
 80. The plating machine of claim 79 wherein the metalcomprises gold.
 81. The plating machine of claim 79 wherein the metalcomprises silver.
 82. The plating machine claim 79 wherein the metalcomprises palladium.
 83. The plating machine of claim 79 wherein themetal comprises platinum.
 84. The plating machine of claim 79,comprising a clip adapted to secure the device to the conveyor, the cliphaving a second metal more noble than bismuth plated thereon.
 85. Theplating machine of claim 84, wherein the second metal comprises gold.86. The plating machine of claim 84, wherein the second metal comprisessilver.
 87. The plating machine of claim 84, wherein the second metalcomprises palladium.
 88. The plating machine of claim 84, wherein thesecond metal comprises platinum.
 89. A method of using a platingmachine, the plating machine having a conveyor, the method comprisingthe acts of: securing a device to be plated to the conveyor, theconveyor having a metal plated thereon, the metal being more noble thancopper; moving the conveyor to immerse the device in an electrolyticbath; and plating a second metal onto at least a portion of the deviceto be plated.
 90. The method set forth in claim 89, further comprisingthe act of plating the metal more noble than copper onto the conveyor.91. The method set forth in claim 89 wherein the metal more noble thancopper comprises gold.
 92. The method set forth in claim 89 wherein themetal more noble than copper comprises silver.
 93. The method set forthin claim 89 wherein the metal more noble than copper comprisespalladium.
 94. The method set forth in claim 89 wherein the metal morenoble than copper comprises platinum.
 95. A method of using a platingmachine, the plating machine having a conveyor, the method comprisingthe acts of: securing a device to be plated to the conveyor, theconveyor having a metal plated thereon, the metal being more noble thanbismuth; moving the conveyor to immerse the device in an electrolyticbath; and plating a second metal onto at least a portion of the deviceto be plated.
 96. The method set forth in claim 95, further comprisingthe act of plating the metal more noble than bismuth onto the conveyor.97. The method set forth in claim 95 wherein the metal more noble thanbismuth comprises gold.
 98. The method set forth in claim 95 wherein themetal more noble than bismuth comprises silver.
 99. The method set forthin claim 95 wherein the metal more noble than bismuth comprisespalladium.
 100. The method set forth in claim 95 wherein the metal morenoble than bismuth comprises platinum.
 101. A method of plating aconveyor belt for use in a plating machine, the method comprising theacts of: providing a conveyor belt; and plating a metal more noble thancopper onto the conveyor belt so that the conveyor belt is adapted foruse in the plating machine without accumulating deposits of a platingmetal thereon.
 102. The method of claim 101 wherein the metal more noblethan copper comprises gold.
 103. The method of claim 101 wherein themetal more noble than copper comprises silver.
 104. The method of claim102 wherein the act of plating comprises employing a plating solutioncomprising Engelhard-Clal Supermex 230 Immersion Au solution.
 105. Themethod of claim 101 wherein the metal more noble than copper comprisespalladium.
 106. The method of claim 105 wherein the act of platingcomprises employing a plating solution comprising Pd/Cl dissolved inHCl.
 107. The method of claim 101 wherein the metal more noble thancopper comprises platinum.
 108. A method of plating a conveyor belt foruse in a plating machine, the method comprising the acts of: providing aconveyor belt; and plating a metal more noble than bismuth onto theconveyor belt so that the conveyor belt is adapted for use in theplating machine without accumulating deposits of a plating metalthereon.
 109. The method of claim 108 wherein the metal more noble thanbismuth comprises gold.
 110. The method of claim 108 wherein the metalmore noble than bismuth comprises silver.
 111. The method of claim 109wherein the act of plating comprises employing a plating solutioncomprising Engelhard-Clal Supermex 230 Immersion Au solution.
 112. Themethod of claim 108 wherein the metal more noble than bismuth comprisespalladium.
 113. The method of claim 112 wherein the act of platingcomprises employing a plating solution comprising Paladium Chloride HCL.114. The method of claim 108 wherein the metal more noble than bismuthcomprises platinum.